PH59192: HIGH CSA CONSUMPTION BY DB2

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When the application issued a NEXT IFI READS call,
  the thread's Cursor Table (CT) control block was different
  from the one used by the FIRST IFI READS call, this caused
  high consumption of ECSA by Db2.
  
  DUMP TITLE DB5P ABND 04E 00E20025 U=CDCPR1 M=N C=121.LOCN=:
  :180.200.171.13  LOC=DSNSLD1 DSNSGMN OFFSET00930
  
  In addition, many erep entries like following reported:
  PIDS/5740XYR00 RIDS/DSNIDM#L RIDS/DSNIDLGR AB/S004E
  PRCS/00C90101 REGS/C0004
  RIDS/DSNTFRCV#R
  SYMPTOM             DESCRIPTION
  -------             -----------
  PIDS/5740XYR00      PROGRAM ID: 5740XYR00
  RIDS/DSNIDM#L       LOAD MODULE NAME: DSNIDM
  RIDS/DSNIDLGR       CSECT NAME: DSNIDLGR
  AB/S004E            SYSTEM ABEND CODE: 004E
  PRCS/00C90101       ABEND REASON CODE: 00C90101
  REGS/C0004          REGISTER/PSW DIFFERENCE FOR R0C:-0004
  RIDS/DSNTFRCV#R     RECOVERY ROUTINE CSECT NAME: DSNTFRCV
  THE REQUESTED SVC DUMP WAS NOT TAKEN. THE DUMP WAS SUPPRESSED
  BYDAE.
  
  +0B4    KEY: CE     LENGTH: 02
  +0B6    5031                                            |&.
  
  This APAR is to relief the high consumption of ECSA, it
  does not fix the root cause of IFCID 306 ABEND04E with
  RC00C90101 IN DSNIDLGR ERQUAL5031
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All Db2 12 and 13 for z/OS users running                     *
  * applications that read the Db2 logs with                     *
  * the IFI READS facility for IFCID 0306, and                   *
  * mode 'N' is specified for the qualification                  *
  * field WQALLMOD.                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * High ECSA usage when the integrity                           *
  * abend was issued by IFCID 0306's NEXT                        *
  * read process. ABEND04E with RC00C90101                       *
  * in DSNIDLGR ERQUAL5031 is one of them.                       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply corrective PTF when available                          *
  ****************************************************************
  When the application program makes IFCID 0306 requests, it
  must allocate a return area in ECSA storage specifically for
  Db2's use. This return area must remain untouched by the
  application between the IFCID 0306 FIRST read request (F call)
  and the NEXT reads request (N call), as Db2 relies on it to
  store critical information for ongoing operations and
  maintains data within the return area across multiple
  application F/N calls, ensuring continuity.
  When the application incorrectly issued a N call with a
  different return area storage than the one obtained for
  the F call, Db2 detected the inconsistency and issued
  IFCID 0306 ABEND04E with RC00C90101 in DSNIDLGR ERQUAL5031.
  With a high volume of incorrect N calls, ECSA storage
  consumption by Db2 was high.
  

Problem conclusion

• Db2 IFCID 0306 is modified to relieve the high consumption of
  ECSA storage. This does not fix the root cause of IFCID 0306
  ABEND04E with RC00C90101 IN DSNIDLGR ERQUAL5031, which detects
  the incorrect IFCID 0306 NEXT read request.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UI95518 UI95519

Modules/Macros

• DSNIDLGR
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RC10 PSY UI95518

     UP24/02/13 P F402 ¢

• RD10 PSY UI95519

     UP24/02/13 P F402 ¢

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.